In recent years, optical coherence tomography apparatuses using a principle of an optical coherence tomography (OCT) have been put into practical use. In the OCT, based on interference light of reflection or scattering light of measurement light entered at a predetermined position of a target of the imaging and reference light received via a reference object, a structure in the depth direction of the position where the measurement light entered is imaged. Using the principle, in the optical coherence tomography apparatus, a two-dimensional or three-dimensional tomographic image can be obtained by fixing an eye to be examined and scanning a retina by changing incident positions of the measurement light. By the processing, an internal structure of the target of the imaging can be observed.
In order to increase a signal-to-noise (S/N) ratio in the tomographic image acquired by the optical coherence tomography apparatus, a technique for performing addition-average processing to a plurality of images and generating a tomographic image having good image quality has been provided. For example, Patent Document 1 discusses a technique for combining a plurality of tomographic images of a retina captured in advance and generating a high-quality still image.